Criminal Psychologist On Reasons Why Shooters Are Male:

Opinion: Why so many shooters are male http://www.cnn.com//2015/06/18/opinions/garbarino-males-become-killers/index.html

Culturally, this is why U.S. law enforcement, military, Secret Service and the President "have to/must be a Caucasian man." American society trains people to fall into a certain role, based upon their race and gender. In the corporate executive-level environments, the same privileged, racist, gang-rapists from the university fraternities continue this pattern of behavior, because it's a common tradition.